Over the past decade, a growing number of companies have been taking groups of adventure-seeking tourists out to chase Tornado Alley's famous cyclones, offering a close-up view of some of the most powerful weather the world has to offer.
Gregg Potter runs his company, F5 Intercept Tours, out of Oklahoma City. He and his partner have been running tours since 1999, a few years after the 1996 movie "Twister" seeded the idea of high-stakes cyclone adventure in potential clients' minds. But in the beginning he didn't have many takers.
"I initially looked at it as a way to look at storms without spending any money on it. In the beginning it was more of a break-even thing," he told AOL News.
The United States is home to about two-thirds of the world's reported tornadoes -- about 1,200 a year. Many of those are in the area known as "Tornado Alley," covering a large section of the Midwestern plains from northern Texas to southern North Dakota. Warm air blowing in from the Gulf of Mexico gets trapped under cooler, dry air from the deserts of the West. When the pressure from those systems bursts, the results are explosive.
The worst tornado in U.S. history tore a swath of destruction 219 miles long across Missouri, Illinois and Indiana in 1925. It killed 695 people.
Since Potter started his business, the market for tornado safaris has only expanded. He takes his clients out from Oklahoma City in a Chevy suburban looking for danger zones, and he remembers when his SUV would be the only vehicle on a long dusty road. Now any given hot spot might have four or five vans giving chase. Shows like Discovery's "Storm Chasers" have raised the profile of these sorts of adventures, and these days Potter typically sells out his spring tour season by November -- and faces dozens of competitors from firms such as Extreme Tornado Tours.
In the end, as with any adventure, it's a gamble.
"In May 2009 we saw a vortex on every trip. Other times, it's empty," Potter said. "It's Mother Nature, you know. Could be a bonanza or could be nothing." For his customers, that uncertainty is part of the thrill.